We know that GB arc KKx20 SSB Goku could affect Zamasu who was roughly equal to SSB Vegito. KKx20 GB arc SSB Goku should at best be a little bit stronger than ToP arc SSG Goku, who could not affect base kefla at all and was an ant to her. It is safe to say that base Kefla is at the bare minimum comparable to SSB Vegito (and likely a lot stronger). Via power scaling, Base Kefla should be fodder compared to Piccolo.

Therefore, adding Piccolo's superior skill and strategy and taking fusion's 10 minute time limit into acccount Vegito Blue would be ROFLstomped by Piccolo.

No. Stop right there with the fanboy nonsense. Piccolo is not more powerful than Gohan. He dropped his guard. You can tell based off of he forest fight they later had with Goku and Tien. Gohan is also not equal to Blue. The point of Blue is incredible Ki control, meaning that at nipping was he going all out in that form, which is why he one punched Gohan when he used Kaioken.